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There is actual fact here, for a non comped gun you want to heaviest possible bullet with the lowest possible amount of powder that burns as fast as possible to attain a desired power level. Impulse will be lower, recoil velocity will be lower, cycle time overall will be longer (good for reliability), and the spring setup can be milder and be far more conducive to a "neutral" handling gun that auto resets to the same place you had it after a recoil event.

It's opposite for a comped gun, you want it as light as possible with huge amounts of slow burning powder and heavier springs to speed up the cycle since if setup properly the gun will be fully neutral and reset/cycle insanely quickly

Out of the ransom rest for 45 ACP I see the lowest recoil (measurable) with fast powders like VVN310 and/or Bullseye and light bullets when driven to the same relatively lethargic velocity as the heavier counterparts. This probably doesn’t hold true for action sports where power factor vice accuracy may be the priority and light bullets therefore require more powder and lose the minor advantage.

Is there any study type data that supports that there are differences between off the shelf 115gr, 124gr or 147gr 9mm ammo regarding impulse and flip? Only anecdotal?

The short answer is...no not to my knowledge at least not all factory ammuniton. The OEM probably doesn’t release/disclose all the load info so it would be difficult to calculate. The only way I could see doing this would to be to work backwards. Use the velocity, charge amount, weapon weight, and bullet weight to determine what the expected recoil is using a calculator (see article above) then use a ransom rest to determine how that plays out based on the propellant speed.

Is there any study type data that supports that there are differences between off the shelf 115gr, 124gr or 147gr 9mm ammo regarding impulse and flip? Only anecdotal?

The context is for a 4.25" barrel Wilson Combat...if that matters.

Thx

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I don't think there were any comparisons of off the shelf ammo.
Too many variables.

However if you load your own, I agree with Striker. When I was competing regularly in IPSC, I used a 45auto with handloaded 230 gr lubed lead bullet and a tiny amount of powder...just enough to make major. The lubed lead required less powder to achieve the same speed.

All else being equal, if two different weight bullets leave the barrel with the same momentum, the slide will recoil with the same velocity. If the slide mass does not change (and it doesn't) the same momentum will result in the same velocity.

Bullet momentum is simply mass times velocity. If you know the velocities and bullet weights, you can determine the relative momentums of the various loads. And that will give you a good approximation of the relative recoil impulses.

Note that the slide gains all of its momentum during the bullet's dwell time in the barrel. This all occurs during the slide's initial 0.12" of travel (approx). From that point on the slide is running on momentum alone.

There is actual fact here, for a non comped gun you want to heaviest possible bullet with the lowest possible amount of powder that burns as fast as possible to attain a desired power level. Impulse will be lower, recoil velocity will be lower, cycle time overall will be longer (good for reliability), and the spring setup can be milder and be far more conducive to a "neutral" handling gun that auto resets to the same place you had it after a recoil event.

It's opposite for a comped gun, you want it as light as possible with huge amounts of slow burning powder and heavier springs to speed up the cycle since if setup properly the gun will be fully neutral and reset/cycle insanely quickly

There is actual fact here, for a non comped gun you want to heaviest possible bullet with the lowest possible amount of powder that burns as fast as possible to attain a desired power level. Impulse will be lower, recoil velocity will be lower, cycle time overall will be longer (good for reliability), and the spring setup can be milder and be far more conducive to a "neutral" handling gun that auto resets to the same place you had it after a recoil event.

It's opposite for a comped gun, you want it as light as possible with huge amounts of slow burning powder and heavier springs to speed up the cycle since if setup properly the gun will be fully neutral and reset/cycle insanely quickly

Do you have any suggestions for your top 3 factory load ammo choices?

I use Wilson match ammo for the lowest recoil that still makes major or syntech 150g for 9mm for the same reason.

Ideally you want the lightest possible round that gets you the power you want with the least powder. Since you are dealing with a 9mm recoil velocity will always be more than a same PF .45 since the springs will be lower rate and allow the side to be at a higher speed when impacting the abutment. Simply because a 9mm always takes more powder relative to a .45 to attain a given power factor since it's a less efficient cartridge. It's complicated because simple math would appear to say same momentum is same recoil but that's just not the case in reality when you actually fire properly sprung .45 and 9mm guns side by side with the same PF.

Bullet momentum is simply mass times velocity. If you know the velocities and bullet weights, you can determine the relative momentums of the various loads. And that will give you a good approximation of the relative recoil impulses.

Two good articles, still simplified, but a little more fidelity. I still suck at physics, just a little less so (barely) than my peers in engineering school.

It's important to note that the secondary recoil effect from the burning powder ejecta is significantly smaller in a 1911. A .223 might have a powder charge that is 1/2 the mass of the bullet. A 9mm powder charge might be less than 1/10 the mass of the bullet, and a .45 powder charge might be less than 1/20 the mass of the bullet.

While this secondary recoil effect is significant in a rifle, it has only a small contribution to the total recoil in a 1911. And furthermore, the difference in this secondary effect among various loads is even smaller yet.

Also, the entire recoil impulse in a 1911 occurs within about 1 millisecond. This recoil energy is spread out over the much longer duration of the felt recoil. The dwell time in the barrel of even the heaviest bullets is not long enough to make a difference in the free recoil duration, which is what we resist against and feel.

A good example of how this initial recoil impulse energy is spread out over the felt recoil duration is in machine gun firing. Full auto fire does not produce a series of recoil "kicks"; it produces a steady push.

Looking only at Federal American Eagle in 115, 124, and 147 gr loads per OP; the 115 has a substantially lower power factor and will have less computed recoil. I doubt it has enough heavier powder charge to make up the difference by "jet effect."
SAAMI spec factory loads of other brands won't likely differ much.

Special purpose ammo like 150 gr Syntech or tailored handloads will make a difference.

Reloading for the same power factor in IDPA and USPSA, I find a 147 gr "subsonic" to be more pleasant and controllable to shoot than 115 gr econoball. But a 124 gr bullet is not bad, because it, too is subsonic and the non-Newtonian effects of flash, blast, and crack! on felt recoil are less.

I wont argue that heavier slower bullets feel softer but I think you have to separate perceived/felt recoil from actual recoil or muzzle flip. Good articles above but one thing I never see addressed is how the body reacts or controls recoil, meaning is it like springs, friction or hydraulic and how it reacts to a sharp impulse as opposed to a slower one.
I know no stated purpose was given but I compete and its all about getting the sights back on the target. I'm different than most of my shooting buddies and prefer a lighter faster bullet and the faster impulse that goes with it.
I mentioned perceived/felt recoil and actual recoil for one reason and that why do heavier/slower bullets tend to hit higher? I'll give an example: Recently I took a new SAA out to try and I had loaded two different bullets, 200gr and 250gr. The 200gr were POA/POI and the 250gr were 6" high. I'm sure you know the answer to this but one would think a slower bullet would drop more.
But in actuality it spends more time in the barrel under recoil and flip and exits at a higher elevation. So in the end did the heavier bullet recoil more, it would seem so?

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